Power diode including oxide semiconductor

• US 8,643,004 B2
• Filed: 10/26/2010
• Issued: 02/04/2014
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Tran, Thanh Y
• Application Number:
  US12/912,315
• Publication Number:
  US 20110101336A1
• Time in Patent Office: 1,197 Days
• Field of Search: 257/E29.296, 257/E29.094, 257/E33.013, 257/43, 257/59, 257/72, 257/76, 257/68, 257/288, 257/296, 257/303, 257/301, 257/306, 257/40, 257/79, 257/80, 257/82, 257/84, 257/88, 257/103, 257/290, 257/291, 257/292, 257/257, 257/258, 257/202, 257/431, 438/104, 438/85, 438/86, 438/754, 438/48, 438/128, 438/149, 438/151, 438/157, 438/283, 438/22, 438/24, 438/28, 438/34, 438/46
• US Class Current: 257/43
• CPC Class Codes: H01L 27/0605 integrated circuits made of compound material, e.g. AIIIBV
• CPC Class Codes: H01L 27/0629 in combination with diodes, or resistors, or capacitors
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/22 including, apart from doping materials or other impurities, only AIIBVI compounds
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/7391 Gated diode structures
• CPC Class Codes: H01L 29/78642 Vertical transistors
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

With a non-linear element (e.g., a diode) with small reverse saturation current, a power diode or rectifier is provided. A non-linear element includes a first electrode provided over a substrate, an oxide semiconductor film provided on and in contact with the first electrode and having a concentration of hydrogen of 5×10¹⁹ atoms/cm³ or less, a second electrode provided on and in contact with the oxide semiconductor film, a gate insulating film covering the first electrode, the oxide semiconductor film, and the second electrode, and third electrodes provided in contact with the gate insulating film and facing each other with the first electrode, the oxide semiconductor film, and the second electrode interposed therebetween or a third electrode provided in contact with the gate insulating film and surrounding the second electrode. The third electrodes are connected to the first electrode or the second electrode. With the non-linear element, a power diode or a rectifier is formed.

Claims

1. A power diode comprising a plurality of non-linear elements, each of the plurality of non-linear elements comprising:

a first electrode provided over a substrate;

an oxide semiconductor film provided on and in contact with the first electrode;

a second electrode provided on and in contact with the oxide semiconductor film;

a gate insulating film covering the first electrode, the oxide semiconductor film, and the second electrode; and

a third electrode provided in contact with the gate insulating film and adjacent to a side surface of the oxide semiconductor film, the third electrode being connected to the first electrode or the second electrode,

wherein the plurality of non-linear elements is connected in series in a forward direction.

2. The power diode according to claim 1, wherein the oxide semiconductor film has a concentration of hydrogen detected by secondary ion mass spectrometry of 5×

10¹⁹ atoms/cm³ or less.

3. The power diode according to claim 1,

wherein the first electrode functions as one of a source electrode and a drain electrode,

wherein the second electrode functions as the other of the source electrode and the drain electrode, and

wherein the third electrode functions as a gate electrode.

4. The power diode according to claim 1, wherein the oxide semiconductor film has a carrier concentration of 5×

10¹⁴ atoms/cm³ or less.

5. The power diode according to claim 1, wherein at least a portion of the gate insulating film which is in contact with the oxide semiconductor film is an oxide insulating film.

6. A semiconductor device comprising the power diode according to claim 1.

7. A power diode comprising a plurality of non-linear elements, each of the plurality of non-linear elements comprising:

a first electrode provided over a substrate;

an oxide semiconductor film provided on and in contact with the first electrode;

a second electrode provided on and in contact with the oxide semiconductor film;

a gate insulating film covering the first electrode, the oxide semiconductor film, and the second electrode; and

a third electrode having a ring shape, the third electrode being provided in contact with the gate insulating film and adjacent to a side surface of the oxide semiconductor film, the third electrode surrounding the second electrode, and the third electrode being connected to the first electrode or the second electrode,

wherein the plurality of non-linear elements is connected in series in a forward direction.

8. The power diode according to claim 7, wherein the oxide semiconductor film has a concentration of hydrogen detected by secondary ion mass spectrometry of 5×

10¹⁹ atoms/cm³ or less.

9. The power diode according to claim 7,

wherein the first electrode functions as one of a source electrode and a drain electrode,

wherein the second electrode functions as the other of the source electrode and the drain electrode, and

wherein the third electrode functions as a gate electrode.

10. The power diode according to claim 7, wherein the oxide semiconductor film has a carrier concentration of 5×

10¹⁴ atoms/cm³ or less.

11. The power diode according to claim 7, wherein at least a portion of the gate insulating film which is in contact with the oxide semiconductor film is an oxide insulating film.

12. A semiconductor device comprising the power diode according to claim 7.